Kinetic analysis of mechanoradical formation during the mechanolysis of dextran and glycogen

• Naoki Doi,
• Yasushi Sasai,
• Yukinori Yamauchi,
• Tetsuo Adachi,
• Masayuki Kuzuya and
• Shin-ichi Kondo

Beilstein J. Org. Chem. 2017, 13, 1174–1183, doi:10.3762/bjoc.13.116

• formation have generally been conducted at low temperature (77 K) [2]. In previous papers we discussed the mechanoradical formation through mechanolysis of synthetic polymers [3][4] and polysaccharides such as amylose and cellulose [5] at room temperature under strictly anaerobic conditions. ESR spectral

• analysis and the progressive changes in the physicochemical properties were also studied in detail. As a representative example, Figure 1 shows the radical structures observed following mechanolysis of cellulose and summarizes the possible reaction sequence. The cellulose mechanoradicals, which were

• copolymers possessing synthetic polymers as branches. Sakaguchi et al. reported a diblock copolymer formation through the mechanochemical reaction of bacterial cellulose and methyl methacrylate in vacuum at 77 K [17]. Solala et al. studied the mechanochemical reaction of cotton in the presence of styrene and

Glycoscience@Synchrotron: Synchrotron radiation applied to structural glycoscience

• Serge Pérez and
• Daniele de Sanctis

Beilstein J. Org. Chem. 2017, 13, 1145–1167, doi:10.3762/bjoc.13.114

• of polysaccharides. Insights into the kinetics of catalytic events observed in the crystalline state are also presented as well as some aspects of structure determination of protein in solution. Keywords: antibodies; carbohydrate binding domains; cellulose; glycosaminoglycans; glycolipids; glycosyl

• molecular crystals of micrometric dimensions or in the form of polycrystalline materials. Small molecule crystals In the quest to solve the crystal structures of cello-oligosaccharides, as model compounds of cellulose, several attempts to grow crystals of β-D-cellotetraose of a size suitable for X-ray

• beam and 3800 independent reflections were collected. The molecular and crystal structure was solved using molecular replacement methods, and refined to an R factor of 0.048 [11]. Those results were useful in the elucidation of the crystalline structure of cellulose. The family of resin glycosides

Fluorescent carbon dots from mono- and polysaccharides: synthesis, properties and applications

• Stephen Hill and
• M. Carmen Galan

Beilstein J. Org. Chem. 2017, 13, 675–693, doi:10.3762/bjoc.13.67

• [13][24]. Similarly, important carbohydrate-based biopolymers such as cellulose, chitin, chitosan, dextran, cyclodextrin, and hyaluronic acid, which differ not only in elemental composition, but also in chemo-physical properties, have also been successfully utilised in the preparation of CDs, where

• molecules composed of monosaccharide units coupled together via glycosidic linkages to form long linear or branched chains. Some of the most common polysaccharides found in nature include cellulose, starch, glycogen or chitin [49]. Upon hydrolysis, these structures break down into smaller fragments such as

• dose and cell death was demonstrated in lung cancer H1299 cells (Scheme 24). Cellulose is the most abundant organic molecule on Earth and is a linear polysaccharide comprised of repeating β-1,4-linked glucose units

Interactions between cyclodextrins and cellular components: Towards greener medical applications?

• Loïc Leclercq

Beilstein J. Org. Chem. 2016, 12, 2644–2662, doi:10.3762/bjoc.12.261

• , polysaccharides serve also as structural components: cellulose for plants and chitin for arthropods. Moreover, saccharides and their derivatives play key roles in the immune system, fertilization, blood clotting, information transfer, etc. For instance, the 5-carbon monosaccharide ribose forms the backbone of the

Isosorbide and dimethyl carbonate: a green match

• Fabio Aricò and
• Pietro Tundo

Beilstein J. Org. Chem. 2016, 12, 2256–2266, doi:10.3762/bjoc.12.218

• industrially relevant products via a chlorine-free and green approach. Synthesis of isosorbide via dimethyl carbonate The current research on the preparation of D-sorbitol is mainly focussed on direct hydrolytic hydrogenation of cellulose [36][37][38][39] via a two-step reaction: Conversion of cellulose into

• reaction media has been also taken into consideration, although their use is limited by solubility problems and environmental concerns [45][46][47][48]. Despite the continuous research on its direct preparation from cellulose, D-sorbitol is nowadays synthesized on industrial scale by hydrogenation of

Silica-supported sulfonic acids as recyclable catalyst for esterification of levulinic acid with stoichiometric amounts of alcohols

• Raimondo Maggi,
• N. Raveendran Shiju,
• Veronica Santacroce,
• Giovanni Maestri,
• Franca Bigi and
• Gadi Rothenberg

Beilstein J. Org. Chem. 2016, 12, 2173–2180, doi:10.3762/bjoc.12.207

• context, levulinic acid, which is easily obtained from cellulose, is valuable since it can be transformed into a variety of industrially relevant fine chemicals. Here we present a simple protocol for the selective esterification of levulinic acid using solid acid catalysts. Silica supported sulfonic acid

• for covering the worldwide demand for non-fuel chemicals [1][2][3][4]. Currently, the main research thrust is directed at lignocellulose, the most abundant fraction of biomass. The mass composition of lignocellulose could be roughly represented by a 5/3/2 ratio of cellulose, hemicellulose and lignin

• , bottom). Moreover, it can be obtained from cellulose with relative ease and high selectivity (see Scheme 1, top) [14]. Levulinic acid esters are of particular interest for the chemical industry [12][13]. Their main current market is represented by the formulation of flavours and fragrances [15], although

Comparing blends and blocks: Synthesis of partially fluorinated diblock polythiophene copolymers to investigate the thermal stability of optical and morphological properties

• Pierre Boufflet,
• Sebastian Wood,
• Jessica Wade,
• Zhuping Fei,
• Ji-Seon Kim and
• Martin Heeney

Beilstein J. Org. Chem. 2016, 12, 2150–2163, doi:10.3762/bjoc.12.205

• . The precipitate was filtered through a cellulose thimble, and the solid purified by Soxhlet extraction with methanol, acetone, and hexane. In order to determine if substantial amounts of P3OT homopolymer still remaining in the sample, a DSC was run on a sample, and after confirmation that this was

• prepared from 2,5-dibromo-3-fluoro-4-octylthiophene (2.25 mL, 0.28 M) was added, and the reaction heated to 70 °C for 2 h before being poured into methanol (200 mL) acidified with a few drops of conc. HCl. The precipitate was filtered through a cellulose thimble, and the solid purified by Soxhlet

Scope and limitations of a DMF bio-alternative within Sonogashira cross-coupling and Cacchi-type annulation

• Kirsty L. Wilson,
• Alan R. Kennedy,
• Jane Murray,
• Ben Greatrex,
• Craig Jamieson and
• Allan J. B. Watson

Beilstein J. Org. Chem. 2016, 12, 2005–2011, doi:10.3762/bjoc.12.187

• -commercial/expensive catalysts, and yield [25][26][27][28][29][30]. Consequently, poor choice of solvent replacement can result in one of industry’s workhorse reactions becoming rather less predictable and robust. In this regard, dihydrolevoglucosenone (Cyrene, Figure 1), accessed in two steps from cellulose

Synthesis and NMR studies of malonyl-linked glycoconjugates of N-(2-aminoethyl)glycine. Building blocks for the construction of combinatorial glycopeptide libraries

• Markus Nörrlinger,
• Sven Hafner and
• Thomas Ziegler

Beilstein J. Org. Chem. 2016, 12, 1939–1948, doi:10.3762/bjoc.12.183

• either simple alkyl chains [15][16], amino alcohols [17][18] or 1,2,3-triazoles [19][20][21]. These building blocks were used for automated SPOT synthesis on a cellulose surface in order to construct complex glycoconjugates which are able to specifically bind to lectins [15][18][20]. In continuation of

Ionic liquids as transesterification catalysts: applications for the synthesis of linear and cyclic organic carbonates

• Maurizio Selva,
• Alvise Perosa,
• Sandro Guidi and
• Lisa Cattelan

Beilstein J. Org. Chem. 2016, 12, 1911–1924, doi:10.3762/bjoc.12.181

• catalysts of light organic carbonates (dimethyl and diethyl carbonate) with complex polyalcohols, such as cellulose. In particular, trioctylphosphonium acetate ([P8881][OAc]) was active for the synthesis of cellulose dialkyl carbonates which find applications as intermediates, supports for the delivery of

Stereodynamic tetrahydrobiisoindole “NU-BIPHEP(O)”s: functionalization, rotational barriers and non-covalent interactions

• Golo Storch,
• Sebastian Pallmann,
• Frank Rominger and
• Oliver Trapp

Beilstein J. Org. Chem. 2016, 12, 1453–1458, doi:10.3762/bjoc.12.141

• quantification of enantiomerization barriers. In order to explore the possibilities of functionalization, we studied modifications of the ligand backbone, e.g., with 3,5-dichlorobenzoyl chloride. Diastereomeric adducts with Okamoto-type cellulose derivatives and on-column deracemization were realized on the

• study, we explored the non-covalent interactions of tetrahydrobiisoindole “NU-BIPHEP(O)s” in solution since they exhibit very strong interactions with Okamoto-type chiral stationary phases (CSPs) in HPLC. Okamoto et al. reported the preparation of short CSP-analogue cellulose and amylose compounds with

• carbamate selector units that are soluble in organic solvents [27][28][29][30]. We prepared cellulose derivative 4 which bears 5-fluoro-2-methylphenylcarbamate binding sites [27] and investigated the formation of diastereomeric adducts with 1b and 3 by 31P{1H} NMR spectroscopy in anhydrous CDCl3

Mutagenic activity of quaternary ammonium salt derivatives of carbohydrates

• Barbara Dmochowska,
• Karol Sikora,
• Anna Woziwodzka,
• Jacek Piosik and
• Beata Podgórska

Beilstein J. Org. Chem. 2016, 12, 1434–1439, doi:10.3762/bjoc.12.138

• . The polymers (oligosaccharides) of D-glucose found, for example, in wood (cellulose) and D-glucosamine present in shells of crabs and insects (chitin), are the widely known ones [1][2]. Another class of carbohydrate biopolymer derivatives – D-ribose and 2-deoxy-D-ribose – constitutes the backbone of

• “green chemistry” solvents, and are considered as a good alternative for classical organic solvents. Among many applications, dissolving cellulose (which was impossible for common solvents), depolymerizing nonnatural polymers, and capturing CO2 appear particularly interesting [15]. Despite their unique

Antibiotics from predatory bacteria

• Juliane Korp,
• María S. Vela Gurovic and
• Markus Nett

Beilstein J. Org. Chem. 2016, 12, 594–607, doi:10.3762/bjoc.12.58

• Myxococcus and Corallococcus, on the one hand, as well as the genus Sorangium, on the other, represent different nutritional types among the myxobacteria. Only the former are bacteriolytic and attack other microorganisms, whereas the latter live as cellulose degraders [36][52][53][54]. Although mere numbers

Supramolecular polymer assembly in aqueous solution arising from cyclodextrin host–guest complexation

• Jie Wang,
• Zhiqiang Qiu,
• Yiming Wang,
• Li Li,
• Xuhong Guo,
• Duc-Truc Pham,
• Stephen F. Lincoln and
• Robert K. Prud’homme

Beilstein J. Org. Chem. 2016, 12, 50–72, doi:10.3762/bjoc.12.7

• substituents of substituted ethyl(hydroxyethyl) cellulose by α-CD, β-CD and their methylated analogs [49]. Guo et al. have shown that the viscosity of aqueous solutions 0.5 wt % in 2% n-C12H25, n-C14H29 or n-C18H37 randomly substituted poly(acrylate) (PAAddn, PAAtdn and PAAodn, respectively) is significantly

• may be decreased by the addition of surfactants as shown by Prud’homme et al. for hydrophobically substituted hydroxyethyl cellulose [51].) Guo et al. showed that the addition of sodium dodecyl sulfate (SDS) to 2 wt % aqueous PAAodn in which the α-CD:n-C18H37 mole ratio is 2:1 to make the mole ratios

Determination of formation constants and structural characterization of cyclodextrin inclusion complexes with two phenolic isomers: carvacrol and thymol

• Miriana Kfoury,
• David Landy,
• Steven Ruellan,
• Lizette Auezova,
• Hélène Greige-Gerges and
• Sophie Fourmentin

Beilstein J. Org. Chem. 2016, 12, 29–42, doi:10.3762/bjoc.12.5

• concentrations ranging from 0 to 10 mM. The obtained mixtures were shaken at 25 °C for 24 h then filtered through a 0.45 μm cellulose filter. The concentrations of 1 or 2 in the filtrate were determined spectrophotometrically at 275 and 277 nm, respectively. Phase solubility profiles were obtained by plotting

Preparation of Pickering emulsions through interfacial adsorption by soft cyclodextrin nanogels

• Shintaro Kawano,
• Toshiyuki Kida,
• Mitsuru Akashi,
• Hirofumi Sato,
• Motohiro Shizuma and
• Daisuke Ono

Beilstein J. Org. Chem. 2015, 11, 2355–2364, doi:10.3762/bjoc.11.257

• . (Japan). The dialysis membrane with a cellulose tube (molecular weight cut-off of 10 kDa) was purchased from the Japan Medical Science Co. Ltd. (Japan) and stored in a moist environment prior to use. Distilled water was used for the purification process. Ultra pure water (Milli-Q) was used for the

Self-assemblies of γ-CDs with pentablock copolymers PMA-PPO-PEO-PPO-PMA and endcapping via atom transfer radical polymerization of 2-methacryloyloxyethyl phosphorylcholine

• Jing Lin,
• Tao Kong,
• Lin Ye,
• Ai-ying Zhang and
• Zeng-guo Feng

Beilstein J. Org. Chem. 2015, 11, 2267–2277, doi:10.3762/bjoc.11.247

• against distilled water using a cellulose membrane (MWCO 3500) for 10 days, changing the water every 6 h, and then freeze dried. Measurements 1H NMR spectra were obtained from a Bruker ARX 400 MHz spectrometer at room temperature with tetramethylsilane (TMS) as the internal standard. The GPC analysis was

Articulated rods – a novel class of molecular rods based on oligospiroketals (OSK)

• Pablo Wessig,
• Roswitha Merkel and
• Peter Müller

Beilstein J. Org. Chem. 2015, 11, 74–84, doi:10.3762/bjoc.11.11

• relatively rigid molecular and supramolecular systems. These systems mainly consist of peptides and proteins (e.g., scleroproteins, globular proteins, and membrane proteins), lipids (e.g., biological membranes), carbohydrates (e.g., cellulose) and nucleic acids (DNA, RNA). The impressive performance of the

Inclusion of trans-resveratrol in methylated cyclodextrins: synthesis and solid-state structures

• Lee Trollope,
• Dyanne L. Cruickshank,
• Terence Noonan,
• Susan A. Bourne,
• Milena Sorrenti,
• Laura Catenacci and
• Mino R. Caira

Beilstein J. Org. Chem. 2014, 10, 3136–3151, doi:10.3762/bjoc.10.331

• experiments were carried out were slightly different from ours, however: an excess of RSV was added to 5 mL of CD solution; the solutions were shaken for 24 h and the suspensions were filtered with cellulose acetate. The results we obtained for the phase-solubility behaviour using β-CD are comparable to those

• , although cellulose acetate was not tested in the present study. Conclusion A variety of methods (physical mixing, kneading, microwave irradiation) of effecting interaction between RSV and three CD hosts (TMA, DMB and TMB) was tested and a combination of thermal analysis and FTIR spectroscopy subsequently

Release of β-galactosidase from poloxamine/α-cyclodextrin hydrogels

• César A. Estévez,
• José Ramón Isasi,
• Eneko Larrañeta and
• Itziar Vélaz

Beilstein J. Org. Chem. 2014, 10, 3127–3135, doi:10.3762/bjoc.10.330

• , sorbitol, cellulose, hemicellulose and pectin). Lactose, sucrose and maltose constitute a significant proportion, especially in infants, whose sole or main source of food is milk [1]. Disaccharides, such as lactose, must be hydrolyzed in order to be absorbed by the human body. For absorption to occur

Conjugates of methylated cyclodextrin derivatives and hydroxyethyl starch (HES): Synthesis, cytotoxicity and inclusion of anaesthetic actives

• Lisa Markenstein,
• Antje Appelt-Menzel,
• Marco Metzger and
• Gerhard Wenz

Beilstein J. Org. Chem. 2014, 10, 3087–3096, doi:10.3762/bjoc.10.325

• membrane cellulose filter, suitably diluted and analyzed using UV spectroscopy. The concentration of midazolam in each solution was determined by measuring its absorbance at 240 nm (ε = 21,240 M−1cm−1). The intrinsic absorption of each CD polymer was taken into account. Cell viability was determined using

First chemoenzymatic stereodivergent synthesis of both enantiomers of promethazine and ethopropazine

• Paweł Borowiecki,
• Daniel Paprocki and
• Maciej Dranka

Beilstein J. Org. Chem. 2014, 10, 3038–3055, doi:10.3762/bjoc.10.322

Synthesis of uniform cyclodextrin thioethers to transport hydrophobic drugs

• Lisa F. Becker,
• Dennis H. Schwarz and
• Gerhard Wenz

Beilstein J. Org. Chem. 2014, 10, 2920–2927, doi:10.3762/bjoc.10.310

• amphiphiles, such as methyl cellulose [47], poly(N-isopropylacrylamide) (pNiPAAm) [48], and also for methylated CDs [49], and CDs completely modified with oligoethylene glycol units [50]. While the LCST transition of the statistical derivative 2b1 was within a rather broad temperature range (30–40 °C), the

Encapsulation of biocides by cyclodextrins: toward synergistic effects against pathogens

• Véronique Nardello-Rataj and
• Loïc Leclercq

Beilstein J. Org. Chem. 2014, 10, 2603–2622, doi:10.3762/bjoc.10.273

• some 2D gCOSY NMR experiments which proved the formation of inclusion complexes. The deposition of the polymer onto cellulose and the antimicrobial activity against E. coli and Salmonella revealed that triclosan was more effective. Atomic force microscopy was used to understand the biocidal mechanism

• , Dong et al. published on the inclusion of ciprofloxacin by grafting β-CD on cellulose fibers (Figure 8) [65]. The β-CD-grafted cellulose was prepared by the formation of CA-β-CD obtained after the dehydration of the two adjacent carboxyl groups of the citric acid (CA) to form a cyclic anhydride, which

• reacts with the hydroxyl groups of β-CD. Next, the CA-β-CDs were covalently bound to the hydroxyl groups of cellulose after the formation of a new cyclic anhydride. Under the best conditions ([CA-β-CD] = 300 g/L, pH 3.4, 15 min, 160 °C), the grafted ratio of β-CD onto cellulose fibers was 9.7%. The

Synthesis and characterization of a hyper-branched water-soluble β-cyclodextrin polymer

• Francesco Trotta,
• Fabrizio Caldera,
• Roberta Cavalli,
• Andrea Mele,
• Carlo Punta,
• Lucio Melone,
• Franca Castiglione,
• Barbara Rossi,
• Monica Ferro,
• Vincenza Crupi,
• Domenico Majolino,
• Valentina Venuti and
• Dominique Scalarone

Beilstein J. Org. Chem. 2014, 10, 2586–2593, doi:10.3762/bjoc.10.271

• solution in ethanol. Then, they were left to dry in air and finally heated on a hot plate. Ultrafiltration was conducted employing cellulose membrane discs with three different cut-off sizes: 3, 10 and 30 kDa. The 3 kDa membrane discs were purchased from Millipore, Bedford, USA, whereas the 10 and 30 kDa